Entinostat Receives ‘Breakthrough Therapy’ Designation for Treatment of Advanced Breast Cancer
Drug set to begin phase III testing (September 11)
The FDA has designated entinostat (Syndax Pharmaceuticals) as a “breakthrough therapy” for the treatment of locally recurrent or metastatic estrogen receptor-positive (ER+) breast cancer when added to exemestane in postmenopausal women whose disease has progressed following nonsteroidal aromatase inhibitor therapy.
Entinostat is an investigational histone deacetylase inhibitor (HDACi) set to begin phase III testing in combination with exemestane in postmenopausal women with metastatic ER+ breast cancer who have progressed on hormonal therapy.
The “breakthrough therapy” designation for entinostat is based on data from the completed phase II ENCORE 301 study, in which entinostat was shown to extend both progression-free survival and overall survival when added to exemestane in postmenopausal women with ER+ metastatic breast cancer whose cancer had progressed after treatment with a nonsteroidal aromatase inhibitor.
Entinostat is an oral inhibitor of class I histone deacetylases — key enzymes that alter the structure of chromatin to control gene expression. This aberrant gene expression can result in reversible, epigenetically-based drug tolerance. Entinostat is designed to selectively target the HDAC isoforms that are most relevant to the biology of tumors, thereby normalizing dysregulated gene expression in cancer cells and restoring the cells’ sensitivity to targeted therapy.
Source: Syndax Pharmaceuticals; September 11, 2013.